A318854 Number of rooted trees with n nodes such that no more than seven isomorphic subtrees extend from the same node.

0, 1, 1, 2, 4, 9, 20, 48, 115, 285, 717, 1837, 4753, 12451, 32878, 87549, 234654, 632813, 1715444, 4672539, 12780498, 35091807, 96684475, 267223388, 740690724, 2058468456, 5734614714, 16011714554, 44799497491, 125587597952, 352696620393, 992168348175

Offset

0,4

Links

Alois P. Heinz, Table of n, a(n) for n = 0..2136

Maple

h:= proc(n, m, t) option remember; `if`(m=0, binomial(n+t, t),
      `if`(n=0, 0, add(h(n-1, m-j, t+1), j=1..min(7, m))))
    end:
b:= proc(n, i) option remember; `if`(n=0, 1, `if`(i<1, 0,
      add(b(n-i*j, i-1)*h(a(i), j, 0), j=0..n/i)))
    end:
a:= n-> `if`(n<2, n, b(n-1$2)):
seq(a(n), n=0..35);

Crossrefs

Column k=7 of A318757.

Sequence in context: A145545 A182378 A318801 * A255638 A215971 A034825

Adjacent sequences: A318851 A318852 A318853 * A318855 A318856 A318857

Keyword

nonn

Author

Alois P. Heinz, Sep 04 2018

Status

approved